Various forms of substrate processing equipment utilize a conveying system to convey a substrate in physical contact with the conveying system. In this case, if foreign matters stick to the substrate or the conveying system, succeeding substrates are successively contaminated. Therefore, it is necessary to periodically stop the equipment to carry out a washing process. For this reason, there is a problem in that an availability factor of the equipment is reduced and a great deal of labor is required. In order to solve the problem, there have been proposed: (1) a method of removing foreign matter sticking on portions of a substrate processing equipment by conveying a substrate having an adhesive substance fastened thereto (for example, Unexamined Japanese Patent Publication 10-154686); and (2) a method of removing foreign matter sticking to the back face of a substrate by conveying a plate-shaped member (Unexamined Japanese Patent Publication 11-87458).
Of these methods, the method of removing foreign matter by conveying a plate-shaped member allows easy conveyance of the plate-shaped member, but is relatively less effective in cleaning foreign matter.
In contrast, the method of removing foreign matter by conveying a substrate having an adhesive substance fastened thereto is relatively more effective in cleaning foreign matter. However, there is a possibility that the adhesive substance and a portion of the equipment might be bonded too strongly to be removed. Therefore, the substrate might not be conveyed reliably. In particular, when a pressure reducing absorption mechanism is used for a chuck table of the equipment, this problem is prevalent.
Further, when the adhesive substance (i.e., the cleaning sheet) is fastened to the substrate, there has been known a method of bonding a cleaning sheet that is larger in size than the substrate to the substrate, and then cutting the cleaning sheet along the shape of the substrate (i.e., a direct cutting method). However, in such a method, refuse from the cut away portion might be generated and might stick to the substrate or the equipment.
Alternatively, another method of bonding a cleaning sheet to a substrate is known where the cleaning sheet is previously punched to the shape of the substrate before being fastened to the substrate (i.e., a precutting method). In this case, the generation of refuse is reduced as compared to the direct cutting method. In some cases, however, an adhesive of the cleaning sheet might leak out of a punched surface during the sheet punching and might stick to an end of the cleaning sheet or substrate so that an appearance is deteriorated or conveyance troubles are caused. Furthermore, in the case in which an adhesive of a polymerization and curing type is used, the adhesive on the end of the cleaning sheet causes defective curing by polymerization inhibition due to oxygen inhibition if the curing is carried out after the sheet punching. Therefore, the contact portion of the substrate processing equipment might be contaminated by the adhesive.